Linear cutting stapler

ABSTRACT

A linear cutting stapler comprises: an upper jaw and a lower jaw ( 5 ) capable of closing or opening relative to each other. A staple cartridge ( 51 ) is disposed at a distal end of the lower jaw ( 5 ). The lower jaw ( 5 ) is U-shaped, and has a staple driving rod ( 3 ) and a blade driving rod ( 4 ) slidably disposed therein. The linear cutting stapler further comprises a safety mechanism. The safety mechanism comprises an engagement member. A notch fitting the engagement member is disposed on a bottom surface of the staple driving rod ( 3 ). The safety mechanism further comprises a floating block ( 1 ). The floating block ( 1 ) may perform longitudinal displacement in the lower jaw ( 5 ). When the floating block ( 1 ) is pressed against the staple cartridge ( 51 ) or an anvil ( 6 ), a top end of the engagement member is driven to perform longitudinal displacement, so that the engagement member is separated from the notch. The linear cutting stapler has a simple structure, is easy to be fabricated, and is safe and reliable.

The present application claims the benefit of priority to Chinese Patent Application No. 201010592492.X titled “LINEAR CUTTING STAPLER” and filed with the State Intellectual Property Office on Dec. 16, 2010, the entire disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present application relates to a linear cutting stapler, which belongs to the technical field of medical instruments.

BACKGROUND OF THE INVENTION

Linear cutting staplers are widely used in surgical operations for wound closure, and internal tissue closure and excision. A typical linear cutting stapler as disclosed in U.S. Pat. No. 5,129,570 performs two functions of stapling and cutting, to remove the redundant tissue while stapling the wound. This kind of linear cutting stapler generally includes two jaws (i.e., an upper jaw and a lower jaw), a closing handle for closing the upper jaw and the lower jaw, a staple anvil and a staple cartridge arranged opposite to each other at the front ends of the upper jaw and lower jaw respectively, a firing piece and a cutter which are arranged in the staple cartridge and are moveable synchronously relative to the staple cartridge, and a push button for driving movement of the firing piece and the cutter. Staples are arranged in the staple cartridge. The firing piece pushes a staple pusher successively and pushes the staples towards the staple anvil. The cutter cuts off the tissue between the staple cartridge and the staple anvil.

The staple cartridge of the instrument can be used for multiple times by being replaced. In clinical application, multiple times of stapling and cutting tissues are often required, and thus the staple cartridge is required to be replaced for many times in an operation. When no staple cartridge is loaded, the push button can be pushed forwards arbitrarily, and then the cutter may be pushed out. This may cause serious consequence as arising from only cutting without stapling. Accordingly, a safety mechanism is provided in the linear cutting staplers in the prior art.

The U.S. Pat. No. 5,129,570 discloses a safety mechanism, in which a safety block with a cutter passage and a staple pushing bar passage is provided in the middle portion of the instrument, and a leaf spring is provided under the cutter. When the instrument is in an opened position, i.e., the upper jaw and the lower jaw are not closed, the leaf spring lifts the cutter upwards, so that the cutter cannot pass through the cutter passage, thereby playing the role of safety. After the staple cartridge is loaded in the instrument, and the two upper and lower jaws are closed, the staple cartridge forces the top portion of the cutter, so that the cutter overcomes the elastic force of the leaf spring and returns to be in alignment with the cutter passage. At this moment, the safety mechanism is deactivated and the instrument can be fired for using.

The U.S. Pat. No. 7,055,730 discloses another safety mechanism, in which a safety block with a cutter pushing bar passage and a staple pushing bar passage is provided in the middle portion of the instrument, with the safety block being rotatable around the instrument under the action of the torsion spring. When the instrument is in an opened position, i.e., the upper jaw and the lower jaw are not closed, the safety block twists such that neither the staple pushing bar nor the cutter pushing bar are allowed to pass through their passages, thereby playing the role of safety. After the staple cartridge is loaded in the instrument, and the upper jaw and the lower jaw are closed, the staple cartridge forces the safety block such that the safety block overcomes the elastic force of the torsion spring and returns into the normal position. That is, the staple pushing bar and the cutter pushing bar align with their own passages on the safety block respectively, so that both the staple pushing bar and the cutter pushing bar are allowed to pass through the safety block. At this moment, the safety mechanism is deactivated and the instrument can be fired for using.

All of the above structures are complicated, and difficult to be manufactured and assembled, as well as costly.

SUMMARY OF THE INVENTION

An object of the present application is to provide a linear cutting stapler having a safety mechanism with simple structure.

The object of the present application will be implemented by the following technical solutions.

A linear cutting stapler includes an upper jaw and a lower jaw capable of being closed or opened relative to each other. A staple cartridge is provided at a distal end of the lower jaw. The lower jaw has a U shape with a staple pushing bar and a cutter pushing bar slidably provided therein. The linear cutting stapler further includes a safety mechanism including an engaging member. A bottom surface of the staple pushing bar is provided with a notch to be engaged with the engaging member. The safety mechanism further includes a floating block displaceable longitudinally in the lower jaw such that when the floating block abuts against the staple cartridge or a staple anvil to drive a longitudinal displacement of the top end of the engaging member, the engaging member is disengaged from the notch.

Further, the bottom end of the floating block is connected to the top end of the engaging member, and the bottom end of the engaging member is connected to the lower jaw. A first through slot and a second through slot for the staple pushing bar and the cutter pushing bar to pass through respectively are provided on the floating block in an axial direction.

Still further, a protrusion to be pressed by the staple cartridge is provided at a distal end of the floating block. By pressing the protrusion, the staple cartridge further drives the top end of the engaging member to displace longitudinally, so that the engaging member is disengaged from the notch.

Still further, a protrusion to be pressed by the staple anvil is provided at a proximal end of the floating block. By pressing the protrusion, the staple anvil further drives the top end of the engaging member to displace longitudinally, so that the engaging member is disengaged from the notch.

Still further, the engaging member is a leaf spring with a bottom end welded to the inner wall of the lower jaw and a top end fixedly connected to the floating block.

Still further, the engaging member is an engaging block at a bottom portion of the floating block. The top end of the engaging block is to be engaged with the notch The bottom end of the engaging block is connected to the bottom surface of the lower jaw by a spring. When the floating block abuts against the staple cartridge or the staple anvil to drive a longitudinal displacement of the engaging member, the bottom portion of the engaging member is disengaged from the notch.

Still further, the engaging block and the floating block are manufactured integrally

Still further, the engaging member is connected to the center of the bottom surface of the lower jaw. The notch is correspondingly arranged at the center of the bottom surface of the staple pushing bar.

Still further, a kidney-shaped protrusion is provided on each of the two sides of the floating block in an axial direction. A kidney-shaped groove fitted with the kidney-shaped protrusion is provided on each of the two inner side walls of the lower jaw. The kidney-shaped protrusion is movable longitudinally in the kidney-shaped groove.

The present application has main beneficial effects such as a simple structure, easy to be manufactured, safe and reliable, as well as good promotion value.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural view of a lower jaw in a first embodiment, with a staple cartridge being not shown;

FIG. 2 is a cross sectional view taken along line A-A in FIG. 1;

FIG. 3 is a partial schematic structural view of the linear cutting stapler in the first embodiment;

FIG. 4 is a cross sectional view taken along line B-B in FIG. 3;

FIG. 5 is a schematic structural view of a lower jaw in a second embodiment, with the staple cartridge being not shown;

FIG. 6 is a cross sectional view taken along line C-C in FIG. 5;

FIG. 7 is a partial schematic structural view of the linear cutting stapler in the second embodiment; and

FIG. 8 is a cross sectional view taken along line D-D in FIG. 7.

REFERENCE NUMERALS IN FIGS. 1 to 8

 1: floating block; 11: first through slot; 12: second through slot; 13: protrusion;  2: leaf spring;  3: staple pushing bar;  4: cutter pushing bar;  5: lower jaw; 51: staple cartridge;  6: staple anvil.

DETAILED DESCRIPTION OF THE INVENTION

The present application provides a linear cutting stapler including an upper jaw and a lower jaw 5 capable of being closed or opened relative to each other. A staple cartridge 51 is arranged at a distal end of the lower jaw 51. The lower jaw 5 has a U shape with a staple pushing bar 3 and a cutter pushing bar 4 slidably arranged therein. The linear cutting stapler further includes a safety mechanism including an engaging member. The bottom surface of the staple pushing bar 3 is provided with a notch to be engaged with the top end of the engaging member. The safety mechanism further includes a floating block 1 which may abut against the staple cartridge 51 or the staple anvil 6 and further drive the top end of the engaging member to displace longitudinally so as to cause the engaging member to be disengaged from the notch. A first through slot 11 and a second through slot 12 for the staple pushing bar 3 and the cutter pushing bar 4 to pass through respectively are arranged on the floating block 1 in an axial direction.

First Embodiment

As shown in FIGS. 1 to 4, in the present application, the linear cutting stapler includes: an upper jaw, a U-shaped lower jaw 5; a staple pushing bar 3 and a cutter pushing bar 4 slidably arranged in the lower jaw 5; a safety mechanism including a leaf spring 2 and a floating block 1, with the bottom end of the leaf spring 2 being welded to the center of the inner wall of the lower jaw 5 and the floating block 1 being connected to the top end of the leaf spring 2. A first through slot 11 and a second through slot 12 for the staple pushing bar 3 and the cutter pushing bar 4 to pass through respectively are provided on the floating block 1 in an axial direction. A notch to be engaged with the top end of the leaf spring 2 is provided at the center of the bottom surface of the staple pushing bar 3. A protrusion 13 to be pressed by the staple cartridge 51 is provided at a distal end of the floating block 1. A kidney-shaped protrusion (not shown) is provided on each of the two sides of the floating block 1 in an axial direction, and a kidney-shaped groove fitted with the kidney-shaped protrusion is provided on each of the two inner side walls of the lower jaw 5. The kidney-shaped protrusion is movable longitudinally in the kidney-shaped groove, so as to guide the floating block 1 to move longitudinally. Of course, a kidney-shaped groove (not shown) may also be provided at each of the two sides of the floating block 1, and a kidney-shaped protrusion (not shown) fitted with the kidney-shaped groove may be provided on each of the two inner side walls of the lower jaw 5.

The principle of operation of the present embodiment is described below. When the linear cutting stapler is not opened or the staple cartridge 51 not mounted, the floating block 1 floats upwards under the action of the leaf spring 2, and then the leaf spring 2 is engaged in the notch of the bottom surface of the staple pushing bar 3, so that the staple pushing bar 3 cannot be pushed forwards, and thus the safety mechanism is activated. When the staple cartridge 51 is mounted to the lower jaw 5, and the upper jaw and the lower jaw are closed, the staple cartridge 51 presses the protrusion 13, so that the leaf spring 2 is pressed by the floating block 1 to move downwards. Then, the floating block returns to a position which allows the staple pushing bar 3 and the cutter pushing bar 4 to pass through. Thus, the leaf spring 2 is disengaged from the notch. Therefore, the safety mechanism is deactivated.

Second Embodiment

As shown in FIGS. 5 to 8, in the present embodiment, the proximal end of the floating block 1 is provided with a protrusion 13 to be pressed by the staple anvil 6. Since other structures are the same as those in the first embodiment, the descriptions of those structures are not repeated here.

The principle of operation of the present embodiment is described below. When the linear cutting stapler is not opened or the staple cartridge 51 not mounted, the floating block 1 floats upwards under the action of the leaf spring 2, and then the leaf spring 2 is engaged in the notch of the bottom surface of the staple pushing bar 3, so that the staple pushing bar 3 cannot be pushed forwards, and thus the safety mechanism is activated. When the staple cartridge 51 is mounted to the lower jaw 5, and the upper jaw and the lower jaw are closed, the staple anvil 6 presses the protrusion 13, so that the floating block 1 forces the leaf spring 2 to move downwards. Then, the floating block returns to a position which allows the staple pushing bar 3 and the cutter pushing bar 4 to pass through. Thus, the leaf spring 2 is disengaged from the notch. Therefore, the safety mechanism is deactivated.

Third Embodiment

In the present embodiment, the engaging member is an engaging block (not shown) to be engaged with the notch. And the bottom end of the engaging block is connected to the bottom surface of the lower jaw 5 by means of a spring (not shown). The engaging block and the floating block 1 are manufactured integrally. Since other structures are the same as those in the first embodiment, the descriptions of those structures are not repeated here.

The principle of operation of the present embodiment is described below. When the linear cutting stapler is not opened or the staple cartridge 51 not mounted, the engaging block floats upwards under the action of the spring, and the floating block 1 floats upwards as well under the action of the engaging block. The top end of the engaging block is engaged in the notch of the bottom surface of the staple pushing bar 3, so that the staple pushing bar 3 cannot be pushed forwards, and thus the safety mechanism is activated. When the staple cartridge 51 is mounted to the lower jaw 5, and the upper jaw and the lower jaw are closed, the staple cartridge 51 presses the protrusion 13, so that the floating block 1 urges the spring to contract so as to drive the engaging block to move downwards. Then, the floating block 1 returns to a position which allows the staple pushing bar 3 and the cutter pushing bar 4 to pass through. Thus, the engaging block is disengaged from the notch. Therefore, the safety mechanism is deactivated.

Fourth Embodiment

In the present embodiment, the engaging member is an engaging block (not shown) with the top end of the engaging block to be engaged with the notch, and the bottom end of the engaging block connected to the bottom surface of the lower jaw 5 by means of a spring (not shown). The engaging block and the floating block 1 are manufactured integrally. Since other structures are the same as those in the first embodiment, the descriptions of those structures are not repeated here.

The principle of operation of the present embodiment is described below. When the linear cutting stapler is not opened or the staple cartridge 51 not mounted, the engaging block floats upwards under the action of the spring, and the floating block 1 floats upwards as well under the action of the engaging block. The top end of the engaging block is engaged in the notch of the bottom surface of the staple pushing bar 3, so that the staple pushing bar 3 cannot be pushed forwards, and thus the safety mechanism is activated. When the staple cartridge 51 is mounted to the lower jaw 5, and the upper jaw and the lower jaw are closed, the staple anvil 6 presses the protrusion 13, so that the floating block 1 urges the spring to contract so as to drive the engaging block to move downwards. Then, the floating block 1 returns to a position which allows the staple pushing bar 3 and the cutter pushing bar 4 to pass through. Thus, the engaging block is disengaged from the notch. Therefore, the safety mechanism is deactivated.

The present application still includes a variety of embodiments. All the technical solutions formed by the equivalent variation or the equivalent modification fall into the protection scope of the present application. 

1. A linear cutting stapler, comprising an upper jaw and a lower jaw capable of being closed or opened relative to each other, with a staple cartridge being provided at a distal end of the lower jaw, the lower jaw having a U shape and being provided therein slidably with a staple pushing bar and a cutter pushing bar, wherein the linear cutting stapler further comprises a safety mechanism comprising an engaging member, a bottom surface of the staple pushing bar is provided with a notch to be engaged with the engaging member; the safety mechanism further comprises a floating block displaceable longitudinally in the lower jaw such that when the floating block abuts against the staple cartridge or a staple anvil to drive a longitudinal displacement of a top end of the engaging member, the engaging member is disengaged from the notch.
 2. The linear cutting stapler according to claim 1, wherein a bottom end of the floating block is connected to the top end of the engaging member, and a bottom end of the engaging member is connected to the lower jaw, a first through slot and a second through slot for the staple pushing bar and the cutter pushing bar to pass through respectively are provided on the floating block in an axial direction.
 3. The linear cutting stapler according to claim 2, wherein a protrusion to be pressed by the staple cartridge is provided at a distal end of the floating block, and wherein by pressing the protrusion, the staple cartridge drives the top end of the engaging member to displace longitudinally, so that the engaging member is disengaged from the notch.
 4. The linear cutting stapler according to claim 2, wherein a protrusion to be pressed by the staple anvil is provided at a proximal end of the floating block, and wherein by pressing the protrusion, the staple anvil drives the top end of the engaging member to displace longitudinally, so that the engaging member is disengaged from the notch.
 5. The linear cutting stapler according to claim 1, wherein the engaging member is a leaf spring with a bottom end welded to an inner wall of the lower jaw and a top end fixedly connected to the floating block.
 6. The linear cutting stapler according to claim 1, wherein the engaging member is an engaging block at a bottom portion of the floating block, with a top end of the engaging block being engaged with the notch, and a bottom end of the engaging block being connected to a bottom surface of the lower jaw by a spring, and wherein when the floating block abuts against the staple cartridge or the staple anvil to drive a longitudinal displacement of the engaging member, a bottom portion of the engaging member is disengaged from the notch.
 7. The linear cutting stapler according to claim 6, wherein the engaging block and the floating block are manufactured integrally.
 8. The linear cutting stapler according to claim 1, wherein the engaging member is connected to the center of a bottom surface of the lower jaw, and the notch is correspondingly arranged at the center of a bottom surface of the staple pushing bar.
 9. The linear cutting stapler according to claim 1, wherein a kidney-shaped protrusion is provided on each of two sides of the floating block in an axial direction, and a kidney-shaped groove fitted with the kidney-shaped protrusion is provided on each of two inner side walls of the lower jaw, the kidney-shaped protrusion is movable longitudinally in the kidney-shaped groove.
 10. The linear cutting stapler according to claim 2, wherein the engaging member is a leaf spring with a bottom end welded to an inner wall of the lower jaw and a top end fixedly connected to the floating block.
 11. The linear cutting stapler according to claim 3, wherein the engaging member is a leaf spring with a bottom end welded to an inner wall of the lower jaw and a top end fixedly connected to the floating block.
 12. The linear cutting stapler according to claim 4, wherein the engaging member is a leaf spring with a bottom end welded to an inner wall of the lower jaw and a top end fixedly connected to the floating block.
 13. The linear cutting stapler according to claim 2, wherein the engaging member is connected to the center of a bottom surface of the lower jaw, and the notch is correspondingly arranged at the center of a bottom surface of the staple pushing bar.
 14. The linear cutting stapler according to claim 3, wherein the engaging member is connected to the center of a bottom surface of the lower jaw, and the notch is correspondingly arranged at the center of a bottom surface of the staple pushing bar.
 15. The linear cutting stapler according to claim 4, wherein the engaging member is connected to the center of a bottom surface of the lower jaw, and the notch is correspondingly arranged at the center of a bottom surface of the staple pushing bar. 